1. Field of the Invention
The present invention relates to a mobile communication system, and more particularly, to a SET-initiated area event triggered positioning method in a mobile communication system capable of initiating an area event triggered session and performing an area event triggered positioning procedure by a SET in a session-based service system.
2. Description of the Background Art
In a mobile communication system, a function group for calculating a position estimate of a mobile terminal is provided at a mobile communication network, and a location service for informing the position estimate to an entity periodically or according to a user's request is provided. The network regarding the location service has various configurations according to inner configurations such as 3GPP or 3GPP2.
A method for calculating a position estimate of a terminal in the mobile communication system includes a cell-id method for informing an ID of a cell to which a terminal belongs, a triangulation method for calculating a position estimate of a terminal by using a triangulation after measuring wave sending time from the terminal to each base station, a GPS using method, etc.
In order to provide location service to a user by using the above methods, signaling and location information have to be sufficiently sent between the terminal and a location server. Accordingly, positioning technologies for providing location service, i.e., a location service based on a position estimate of the terminal is being spread. The position technologies may be provided through a user plane and a control plane. As a representative of the position technologies through the user plane, a secure user plane location (SUPL) method has been well known.
The SUPL method is efficient in sending location information necessary to calculate a position estimate of a base station, in which location assistance information such as a GPS assistance is sent, and a user plane data bearer is used to carry protocols regarding the positioning technology between the terminal and a network.
An SUPL network regarding a location service in a positioning system includes an SUPL Agent, an SUPL Location Platform (SLP), an SUPL Enabled Terminal (SET), etc. The SUPL Agent indicates a logic service access point using substantially measured location information, and the SLP indicates an SUPL service access point inside a network for accessing network resources so as to obtain location information.
The SET is a device communicating with an SUPL network using an SUPL interface (i.e., a user terminal of UMTS, a mobile station of GSM, a laptop computer having an IS-95 MS function or a SET function, or a PDA). The SET may be various mobile terminals connected to one another through a WLAN.
The SET supports procedures defined in an SUPL by being connected to a network through a user plane bearer. Herein, a network to which a user has been originally registered is defined as a Home Network, and a network of the user's moving area rather than the Home Network is defined as a Visited Network. An SLP of the Home Network is defined as an Home-SLP, and an SLP of the Visited Network is defined as a V-SLP (Visited-SLP). When an SUPL procedure is started on the network, an SLP to which an external client is firstly connected is defined as an R-SLP (Requesting SLP). The R-SLP is a logical entity, and may be or may not be same as the H-SLP. A SET having an object to verify a current position estimate is defined as a target SET.
The SLP of the network consists of an SPC (SUPL Positioning Center) for calculating a position estimate, and an SLC (SUPL Location Center) for performing roaming, resource management, etc. The SET may calculate location information by indirectly communicating with the SPC via the SLC (Proxy mode), or may calculate location information by directly communicating with the SPC (Non-proxy mode).
In the related art, even if an SUPL-based immediate positioning method is disclosed, a SET-initiated area event triggered positioning method in an SUPL-based system is not disclosed